We have investigated the mechanisms of oncogenes regulation in human malignancies. Deregulation of the c-myc gene accompanies all cases of human Burkitt's lymphoma (BL) and many other types of human tumors, therefore the mechanism underlying the transcriptional regulation of the c-myc gene and the role of its gene product have been investigated. The three major projects are the following: A. Transcriptional regulation of the c-myc oncogene in normnal and neoplastic cells. B. Effect of differentiating agents on the function of transcription factors and their role in the regulation of the c-myc gene. C. Search for the function of the c-myc proteins.